Don`t we all sound like experts here... This is what I hate most about forums... you get all these clue-less people trying to give other`s advise.... How funny that is... a clue less person giving another clue-less person advise... isn`t that like "Calling the tea kettle black"...
Ok, so you say that the web site is 99% complete and that you can launch if you wanted to correct? So what is holding you back? Why not launch and try to get ahold of him in the mean time? I don`t think that a username and password is a big thing to cry over, try emailing him or you say you have a paper trail of conversations, and emails.
Have you ever tried revisiting all your emails? What if you do have the password and information but you don`t remember? This happened to me once.... and Boy did I feel Stupid afterwards.
At 99% complete, I don`t think it would be a good idea to kill a good relationship with your developer since he has delivered 99% of the work. at 7 Grand it sounds like a very large project. If that`s the case, don`t burn your bridges because if he developed the site, that means he has the blue prints to your site.
Which means, you might need him in the near future aside what all these clowns have to say on this forum, don`t take their advise, right off the bat I see two starving designers "Im not going to point fingers" that want your business, but do you think they can deliver?
The key to your game is, call him or them, be cool about it, and move on if that`s what you wish to do, but again.... he might be the only person that understands your site`s functionality and if he has delivered 99% of the project what are you crying about? Be glad that he delivered, One of my customers got burned for 10K and never even got a layout mock up.
Don`t be upset... what if something did happen to him or someone in his family? Have you been courteous to ask? or you don`t care about anything else than your username and password?
I`m not going to lie to you... I am a small time web designer.... Most of my client base comes from word of mouth... I don`t usually deal with large clients.... but if I found out that one of my clients wanted to take me to court, I would drop them like a bad habit. Fafaflo... You`re a scary person to do business with